// CircleTool.java
// (C) 2007 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 22.05.2007 on http://yacy.net
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// LICENSE
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package net.yacy.visualization;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
public class CircleTool {
private static short[][] circles = new short[0][];
private static short[] getCircleCoords(final short radius) {
if ((radius - 1) < circles.length) return circles[radius - 1];
// read some lines from known circles
Set<String> crds = new HashSet<String>();
//crds.add("0|0");
String co;
for (short i = (short) Math.max(0, circles.length - 2); i < circles.length; i++) {
for (short j = 0; j < circles[i].length; j = (short) (j + 2)) {
co = circles[i][j] + "|" + circles[i][j + 1];
if (!(crds.contains(co))) crds.add(co);
}
}
// copy old circles into new array
short[][] newCircles = new short[radius][];
System.arraycopy(circles, 0, newCircles, 0, circles.length);
// compute more lines in new circles
short x, y;
List<short[]> crc;
short r1;
for (short r = (short) circles.length; r < newCircles.length; r++) {
r1 = (short) (r + 1);
crc = new ArrayList<short[]>();
for (short a = 0; a < 2 * (r + 1); a++) {
x = (short) (r1 * Math.cos(Math.PI * a / (4 * r1)));
y = (short) (r1 * Math.sin(Math.PI * a / (4 * r1)));
co = x + "|" + y;
if (!(crds.contains(co))) {
crc.add(new short[]{x, y});
crds.add(co);
}
x = (short) (((double) r + 0.5) * Math.cos(Math.PI * a / (4 * r1)));
y = (short) (((double) r + 0.5) * Math.sin(Math.PI * a / (4 * r1)));
co = x + "|" + y;
if (!(crds.contains(co))) {
crc.add(new short[]{x, y});
crds.add(co);
}
}
// put coordinates into array
//System.out.print("Radius " + r + " => " + crc.size() + " points: ");
newCircles[r] = new short[2 * (crc.size() - 1)];
short[] coords;
short i2 = 0;
for (short i = 0; i < crc.size() - 1; i++) {
coords = crc.get(i);
newCircles[r][i2++] = coords[0];
newCircles[r][i2++] = coords[1];
//System.out.print(circles[r][i][0] + "," +circles[r][i][1] + "; ");
}
//System.out.println();
}
crc = null;
crds = null;
// move newCircles to circles array
circles = newCircles;
newCircles = null;
// finally return wanted slice
return circles[radius - 1];
}
public static void circle(final RasterPlotter matrix, final int xc, final int yc, final int radius, final int intensity) {
if (radius == 0) {
//matrix.plot(xc, yc, 100);
} else {
final short[] c = getCircleCoords((short) radius);
short x, y;
short limit = (short) (c.length / 2);
short i2 = 0;
for (short i = 0; i < limit; i++) {
x = c[i2++];
y = c[i2++];
matrix.plot(xc + x , yc - y - 1, intensity); // quadrant 1
matrix.plot(xc - x + 1, yc - y - 1, intensity); // quadrant 2
matrix.plot(xc + x , yc + y , intensity); // quadrant 4
matrix.plot(xc - x + 1, yc + y , intensity); // quadrant 3
}
}
}
public static void circle(final RasterPlotter matrix, final int xc, final int yc, final int radius, int fromArc, int toArc) {
// draws only a part of a circle
// arc is given in degree
while (fromArc > 360) fromArc -=360;
while (fromArc < 0 ) fromArc +=360;
while ( toArc > 360) toArc -=360;
while ( toArc < 0 ) toArc +=360;
if (radius == 0) {
//matrix.plot(xc, yc, 100);
} else {
final short[] c = getCircleCoords((short) radius);
final short q = (short) (c.length / 2);
final short[] c4x = new short[q * 4];
final short[] c4y = new short[q * 4];
short a0, a1, a2, a3, b0, b1;
for (short i = 0; i < q; i++) {
b0 = (short) (2 * (i ));
b1 = (short) (2 * (q - 1 - i));
a0 = c[b0 ];
a1 = c[b0 + 1];
a2 = c[b1 ];
a3 = c[b1 + 1];
c4x[i ] = a0 ; // quadrant 1
c4y[i ] = (short) (-a1 - 1); // quadrant 1
c4x[i + q] = (short) ( 1 - a2); // quadrant 2
c4y[i + q] = (short) (-a3 - 1); // quadrant 2
c4x[i + 2 * q] = (short) ( 1 - a0); // quadrant 3
c4y[i + 2 * q] = a1 ; // quadrant 3
c4x[i + 3 * q] = a2 ; // quadrant 4
c4y[i + 3 * q] = a3 ; // quadrant 4
}
if (fromArc == toArc) {
int i = q * 4 * fromArc / 360;
matrix.plot(xc + c4x[i], yc + c4y[i], 100);
} else if (fromArc > toArc) {
// draw two parts
for (int i = q * 4 * fromArc / 360; i < q * 4; i++) {
matrix.plot(xc + c4x[i], yc + c4y[i], 100);
}
for (int i = 0; i < q * 4 * toArc / 360; i++) {
matrix.plot(xc + c4x[i], yc + c4y[i], 100);
}
} else {
// can be drawn in one part
for (int i = q * 4 * fromArc / 360; i < q * 4 * toArc / 360; i++) {
matrix.plot(xc + c4x[i], yc + c4y[i], 100);
}
}
}
}
}